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Gaussian state approximation of quantum many-body scars
by Wouter Buijsman, Yevgeny Bar Lev
This Submission thread is now published as
Submission summary
| Authors (as registered SciPost users): | Yevgeny Bar Lev · Wouter Buijsman |
| Submission information | |
|---|---|
| Preprint Link: | scipost_202307_00041v4 (pdf) |
| Date accepted: | 2024-08-09 |
| Date submitted: | 2024-07-31 16:03 |
| Submitted by: | Buijsman, Wouter |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approaches: | Theoretical, Computational |
Abstract
Quantum many-body scars are atypical, highly nonthermal eigenstates embedded in a sea of thermal eigenstates that have been observed in, for example, kinetically constrained quantum many-body models. These special eigenstates are characterized by a bipartite entanglement entropy that scales as most logarithmically with the subsystem size. We use numerical optimization techniques to investigate if quantum many-body scars of the experimentally relevant PXP model can be well approximated by Gaussian states. Gaussian states are described by a number of parameters that scales quadratically with system size, thereby having a much lower complexity than generic quantum many-body states, for which this number scales exponentially. We find that while quantum many-body scars can typically be well approximated by (symmetrized) Gaussian states, this is not the case for ergodic (thermal) eigenstates. This observation suggests that the non-ergodic part of the PXP Hamiltonian is related to certain quadratic parent Hamiltonians, thereby hinting on the origin of the quantum many-body scars.
Author indications on fulfilling journal expectations
- Provide a novel and synergetic link between different research areas.
- Open a new pathway in an existing or a new research direction, with clear potential for multi-pronged follow-up work
- Detail a groundbreaking theoretical/experimental/computational discovery
- Present a breakthrough on a previously-identified and long-standing research stumbling block
Author comments upon resubmission
We are grateful to the Referee for their constructive comments and recommendation to accept our manuscript for publication in SciPost Physics. Please find below our reply to both points in the report.
Yours sincerely,
Wouter Buijsman
Yevgeny Bar Lev
List of changes
- Expanded the discussion of the Jordan-Wigner transform with a remark on the choice of the root.
-Commented on the translational invariance of the trial wavefunctions.
Published as SciPost Phys. 17, 055 (2024)